I was hoping that
ALLOW_READING_INDICATOR = false
would remove the reading indicator at the bottom of the screen. No such luck, or I didn't have the magical incantation required. My justification toggle setting is still there but this didn't stick.
Personally I would like the reading indicator to go away like the status bar at the top, and give me the whole screen to read on (in PDF mode also). MENU button could reveal both.